Handling device and computer program product

ABSTRACT

A handling device according to an embodiment includes a manipulator, a normal grid generation unit, a hand kernel generation unit, a calculation unit, and a control unit. The normal grid generation unit converts a depth image into a point cloud, generates spatial data including an object to be grasped that is divided into a plurality of grids from the point cloud, and calculates a normal vector of the point cloud included in the grid using spherical coordinates. The hand kernel generation unit generates a hand kernel of each suction pad. The calculation unit calculates ease of grasping the object to be grasped by a plurality of suction pads based on a 3D convolution calculation using a grid including the spatial data and the hand kernel. The control unit controls a grasping operation of the manipulator based on the ease of grasping the object to be grasped by the plurality of suction pads.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2020-155714, filed on Sep. 16, 2020; the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a handling device and a computer program product.

BACKGROUND

Conventionally, a robot system that automates an object handling work, such as a picking automation system that handles baggage or the like stacked in a logistics warehouse has been known. Such a robot system automatically calculates a grasping position or posture of an object and a placement position or posture in a bin based on sensor data such as image information, and actually executes grasping or release and placement by a robot having a robotic grasping hand like a suction pad. In recent years, with the development of a machine learning technology, a technology of realizing an appropriate operation of a robot by learning has been used.

However, in the conventional technologies, in a case where the number or a position of suction pads is changed, an appropriate handling operation cannot be determined unless re-learning using teacher data for learning the ease of grasping again is performed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating an example of a configuration of a handling device according to an embodiment;

FIG. 2A is a diagram for describing a handling tool according to the embodiment;

FIG. 2B is a diagram for describing a suction pad according to the embodiment;

FIG. 3 is a diagram illustrating an example of a functional configuration of a controller according to the embodiment;

FIG. 4 is a diagram illustrating an example of a functional configuration of a planning unit according to the embodiment;

FIG. 5 is a diagram for describing an example of processing of an evaluation unit according to the embodiment;

FIG. 6 is a diagram illustrating an example of a functional configuration of a normal grid generation unit according to the embodiment;

FIG. 7 is a diagram for describing a definition of a normal according to the embodiment;

FIG. 8A is a diagram illustrating a first example of a posture of the handling tool according to the embodiment;

FIG. 8B is a diagram illustrating a second example of a posture of the handling tool according to the embodiment;

FIG. 8C is a diagram illustrating a third example of a posture of the handling tool according to the embodiment;

FIG. 9 is a diagram illustrating an example of a position of a tool center point (TCP) and hand kernels according to the embodiment;

FIG. 10 is a diagram for describing a 3D convolution according to the embodiment;

FIG. 11 is a diagram for describing a calculation example of a convolution according to the embodiment;

FIG. 12 is a flowchart illustrating an example of a handling method according to the embodiment; and

FIG. 13 is a diagram illustrating an example of a hardware configuration of a controller according to the embodiment.

DETAILED DESCRIPTION

A handling device according to an embodiment includes a manipulator, a normal grid generation unit, a hand kernel generation unit, a calculation unit, and a control unit. The manipulator includes a handling tool including a plurality of suction pads and an arm. The normal grid generation unit converts a depth image including one or more objects to be grasped into a point cloud, generates spatial data including the object to be grasped that is divided into a plurality of grids from the point cloud, and calculates a normal vector of the point cloud included in the grid using spherical coordinates. The hand kernel generation unit generates a hand kernel of each of the suction pads based on a position of each of the suction pads in the handling tool and the Posture of the handling tool. The calculation unit calculates ease of grasping the object to be grasped by the plurality of suction pads based on a 3D convolution calculation using a grid including the spatial data and the hand kernel. The control unit controls a grasping operation of the manipulator based on the ease of grasping the object to be grasped by the plurality of suction pads. Hereinafter, embodiments of a handling device and a computer program product will be described in detail with reference to the accompanying drawings.

Example of Device Configuration

FIG. 1 is a schematic diagram illustrating an example of a configuration of a handling device 100 according to an embodiment. The handling device 100 according to the embodiment includes an arm 1, a handling tool 2, a controller 3, a camera 4, and a sensor 5. The arm 1 is an articulated robot driven by a plurality of servo motors. The handling tool 2 includes one or more suction pads. The suction pad sucks and grasps an object 102 to be grasped, which is a target to be grasped. The suction pad will be described later with reference to FIGS. 2A and 2B.

The arm 1 and the handling tool 2 operate as a manipulator (robot arm). The camera 4 is attached to the handling tool 2 and captures a depth image of the object 102 to be grasped existing in an article container 101. Note that the number and shapes of objects 102 to be grasped existing in the article container 101 may be arbitrary. The sensor 5 measures information such as a joint angle, a joint force and the like of the arm 1.

Example of Handling Tool

FIG. 2A is a diagram for describing the handling tool 2 according to the embodiment. As illustrated in FIG. 2A, the handling tool 2 has a degree of freedom of rotation by a tool rotation axis 103. In addition, the handling tool 2 according to the embodiment includes suction pads 6 a and 6 b. Note that the number of suction pads included in the handling tool 2 is not limited to two and may be arbitrary.

FIG. 2B is a diagram for describing the suction pads 6 a and 6 b according to the embodiment. A diameter of the suction pads 6 a and 6 b is D. A distance between the center of the suction pad 6 a and the center of the suction pad 6 b is d. Sizes and shapes of the suction pads 6 a and 6 b according to the embodiment are the same as each other. Therefore, hereinafter, in a case where the suction pads 6 a and 6 b are not distinguished from each other, they are simply referred to as a suction pad 6.

Example of Function Configuration of Controller

FIG. 3 is a diagram illustrating an example of a functional configuration of the controller 3 according to the embodiment. The controller 3 according to the embodiment includes a processing unit 31, a planning unit 32, and a control unit 33.

The processing unit 31 processes data acquired by the camera 4 and the sensor 5. For example, the processing unit 31 performs noise removal processing of the depth image captured by the camera 4. In addition, for example, the processing unit 31 performs background exclusion processing for excluding depth information other than the object 102 to be grasped (for example, the article container 101, the ground and the like) from the depth image. In addition, for example, the processing unit 31 performs image resizing processing for resizing a size of the depth image to a size of the depth image input to the planning unit 32.

The planning unit 32 calculates a heat map indicating the ease of grasping by one suction pad 6 for each pixel coordinate of an image by deep learning. Note that the planning unit 32 calculates a heat map indicating the ease of grasping by the suction pad 6 a and a heat map indicating the ease of grasping by the suction pad 6 b, respectively, in a case where types of the suction pads 6 a and 6 b are not the same as each other (sizes, shapes and the like of the suction pads 6 a and 6 b are not the same as each other).

Next, the planning unit 32 calculates a heat map indicating the ease of grasping by a plurality of suction pads 6 by a 3D convolution based on the heat map indicating the ease of grasping by one suction pad 6. In an example of the embodiment, the planning unit 32 calculates a heat map indicating the ease of grasping using both the suction pads 6 a and 6 b. Further, the planning unit 32 ranks the ease of grasping, and inputs an optimum grasping posture in which the object 102 to be grasped is most easily grasped to the control unit 33.

The control unit 33 controls behavior of the manipulator (the arm 1 and the handling tool 2) that grasps the object 102 to be grasped according to the optimum grasping posture of the handling tool 2 generated by the planning unit 32.

Example of Function Configuration of Planning Unit

FIG. 4 is a diagram illustrating an example of a functional configuration of the planning unit according to the embodiment. The planning unit 32 according to the embodiment includes an evaluation unit 321, a normal grid generation unit 322, a hand kernel generation unit 323, a calculation unit 324, and an adjustment unit 325.

The evaluation unit 321 calculates an evaluation value indicating the ease of grasping the object 102 to be grasped by one suction pad 6 based on the depth image. For example, the evaluation unit 321 calculates an evaluation value of each point of the object 102 to be grasped by the heat map based on the depth image.

The normal grid generation unit 322 generates a normal grid based on the depth image, the heat map indicating the ease of grasping by one suction pad 6, and point cloud information converted from the depth image. Details of a method of generating the normal grid will be described later with reference to FIGS. 6 and 7.

The hand kernel generation unit 323 generates a hand kernel of each suction pad 6. Details of the hand kernel will be described later with reference to FIG. 9.

The calculation unit 324 performs a 3D convolution calculation between the normal grid and the hand kernel of each suction pad 6 to find a hand posture that can suck the object 102 to be grasped and a position of the suction pad 6 with respect to the hand posture. Then, the calculation unit 324 calculates a heat map (first heat map) indicating the ease of grasping with the plurality of suction pads 6 from the heat map indicating the ease of grasping with one suction pad 6.

The adjustment unit 325 adjusts a posture of the handling tool 2 and a position where the object 102 to be grasped is grasped by the handling tool 2 based on the first heat map. The adjustment unit 325 ranks the ease of grasping, and calculates a position of a point that is most easily grasped and a grasping posture of the manipulator (the arm 1 and the handling tool 2) represented using the normal.

Example of Processing of Evaluation Unit

FIG. 5 is a diagram for describing an example of processing of the evaluation unit 321 according to the embodiment. The evaluation unit 321 calculates the evaluation value indicating the ease of grasping the object 102 to be grasped by one suction pad based on the depth image including one or more objects 102 to be grasped. The evaluation value is a value in which a distance to the center of a region that can be sucked, flatness of the region that can be sucked, and an inclination of the region that can be sucked are considered in a composite manner. Specifically, the evaluation unit 321 calculates the evaluation value using a neural network having an input layer receiving an input of the depth image, an intermediate layer, and an output layer outputting a heat map (second heat map). In the embodiment, each pixel of the heat map indicates a posture at the time of grasping an object at a position of a world coordinate system for a pixel position and an evaluation value (score indicating the ease of grasping).

Example of Functional Configuration of Normal Grid Generation Unit

FIG. 6 is a diagram illustrating an example of a functional configuration of the normal grid generation unit 322 according to the embodiment. The normal grid generation unit 322 according to the embodiment includes a conversion unit 331, a filter unit 332, and a generation unit 333.

The conversion unit 331 receives the depth image from the processing unit 31. The conversion unit 331 converts a 2.5-dimensional depth image captured by the camera 4 into a point cloud (three-dimensional point cloud data) using a camera matrix.

The filter unit 332 generates grasping target point cloud data by deleting points for pixels whose evaluation values are lower than a threshold value (that is, at which it is difficult to grasp the object) from the point cloud using the heat map output from the evaluation unit 321.

The generation unit 333 generates a normal grid from the grasping target point cloud data input from the filter unit 332. Specifically, the generation unit 333 divides a space in which the camera 4 can capture an image into a cube (grid) of 1×1×1 [m]. The generation unit 333 stores an average value of normal vectors representing directions of normal defined in spherical coordinates of points that are in the grid in each grid to generate the normal grid. Each grid including spatial data including the object 102 to be grasped is used for a 3D convolution calculation for calculating the ease of grasping of the object 102 to be grasped.

Definition Example of Normal

FIG. 7 is a diagram for describing a definition of the normal according to the embodiment. The normal according to the embodiment is defined in spherical coordinates. Generally, a normal vector n is defined as [n_(x), n_(y), n_(z)]. A norm ρ of the normal vector n is (n_(x) ²+n_(y) ²+n_(z) ²)^(1/2). Since n is a unit vector, ρ=1. The normal vector n is represented by a two-dimensional vector by converting the normal vector n into spherical coordinates (ϕ, θ) illustrated in FIG. 7. Therefore, a calculation amount of calculation in which the normal vector n is used can be reduced.

If the spherical coordinates (0, 0) are used, [n_(x),n_(y),n_(z)] is represented by the following Equation 1.

n _(z)=ρ cos θ

n _(x)=ρ sin θ cos θ

n=ρ sin θ sin θ  (1)

Expression Example of Posture of Handling Tool

The posture of the handling tool 2 according to the embodiment is expressed by H_(ϕ) and H_(θ) using angles of spherical coordinates, similar to the definition of the normal described above.

FIG. 8A is a diagram illustrating a first example of a posture of the handling tool 2 according to the embodiment. FIG. 8A illustrates a case where H_(ϕ)=90 and H_(θ)=0. TCP indicates a tool center point. FIG. 8A illustrates a case where an inclination does not occur in the handling tool 2.

FIG. 8E is a diagram illustrating a second example of a posture of the handling tool 2 according to the embodiment. FIG. 8B illustrates a case where H_(ϕ)=90 and H_(θ)=45. FIG. 8B illustrates a case where an inclination of 45° occurs in the handling tool 2 by an angle θ (see FIG. 7) in an xy plane.

FIG. 8C is a diagram, illustrating a third example of a posture of the handling tool 2 according to the embodiment. FIG. 8C illustrates a case where H_(ϕ)=45 and H_(θ)=0. FIG. 8C illustrates a case where an inclination of 45° occurs in the handling tool 2 by an angle θ (see FIG. 7) in a yz plane.

Any posture of the handling tool 2 including the suction pads 6 a and 6 b can be expressed by any combination of H_(ϕ) and H_(θ).

Example of Hand Kernel

FIG. 9 is a diagram illustrating an example of a position of a TCP and hand kernels according to the embodiment. The hand kernel generation unit 323 generates hand kernels of the suction pads 6 a and 6 b. The hand kernel generation unit 323 expresses the posture of the handling tool 2 by H_(ϕ) and H_(θ) using the spherical coordinates to generate hand kernels corresponding to H_(ϕ) and H_(θ) for the respective suction pads 6.

Specifically, first, the hand kernel generation unit 323 divides a space representing the posture of the handling tool 2 into a grid of 1×1×1 as in a case of generating the normal grid to create a hand kernel, because the distance between the centers is d. As illustrated in FIG. 9, the center of the hand kernel is a position of the TCP.

Next, the hand kernel generation unit 323 calculates an index (X, Y, Z) in the hand kernel expressing a position and a posture of the suction pad 6 by a relative position and a relative posture with respect to the posture of the handling tool 2, when the posture (H_(ϕ) and H_(θ) of the handling tool 2 is determined. For example, in a case where the handling tool 2 includes two suction pads 6 a and 6 b as in the embodiment, Index_(R)(X_(R),Y_(R),Z_(R)) of a right suction pad 6 b is calculated as a right hand kernel by the following Equation 2, and Index_(L)(X_(L),Y_(L),Z_(L)) of a left suction pad 6 a is calculated as a left hand kernel by the following Equation 3.

Z _(R)=int(0.5d cos H _(θ))

X _(R)=int(0.5d sin H _(θ) cos H _(θ))

Y _(R)=int(0.5d sin H _(θ) sin H _(θ))  (2)

Z _(L)=int(0.5d cos(π−H _(θ)))

X _(L)=int(0.5d sin(π−H _(θ))cos(H _(θ)+π))

Y _(L)=int(0.5d sin(π−H _(θ))sin(H _(θ)+π))  (3)

Here, int ( ) indicates a function that approximates a value in ( ) with an integer value.

FIG. 9 illustrates an example of the left and right hand kernels in the case where the posture of the handling tool 2 is H_(ϕ)=90 and H_(θ)=0 (see FIG. 8A). Position 201 of the left hand kernel is represented by the Index_(L)(X_(L),Y_(L),Z_(L)). A value of the left hand kernel is 1.0 at a position of the Index_(L)(X_(L),Y_(L),Z_(L)) and is empty (nan) at the other positions. Similarly, position 202 of the right hand kernel is represented by the Index_(R)(X_(R),Y_(R),Z_(R)). A value of the right hand kernel is 1.0 at a position of the Index_(R)(X_(R),Y_(R),Z_(R)) and is empty (nan) at the other positions.

In addition, a distance between the Index_(L)(X_(L),Y_(L),Z_(L)) and the Index_(R)(X_(R),Y_(R),Z_(R)), that is, ∥Index_(L)(X_(L),Y_(L),Z_(L))−Index_(R)(X_(R),Y_(R),Z_(R))∥≈d.

Example of Processing of Calculation Unit

FIG. 10 is a diagram for describing a 3D convolution according to the embodiment. The calculation unit 324 according to the embodiment performs a 3D convolution calculation between the left hand kernel and the normal grid and a 3D convolution calculation between the right hand kernel and the normal grid.

A problem of calculating a grasping posture in which the object 102 to be grasped can be sucked by the plurality of suction pads 6 is considered to calculate points satisfying two conditions that a distance between two points (a grasping point of one suction pad and a grasping point of the other suction pad 6) of grasping points that can be sucked by one suction pad 6 is d and normals of the two points are parallel with each other. If these two points are calculated by a general Euclidean distance calculation equation and a vector parallelism discriminant, a calculation amount becomes enormous.

For that reason, the calculation unit 324 finds an approximate solution of the points satisfying the above two conditions at a high speed by a difference between 3D convolution calculation results of each hand kernel. A 3D convolution calculation result between the hand kernel and the normal grid includes a position that can be sucked by the suction pad 6 and a normal of that position in a grid having the same size as that of the normal grid.

The calculation unit 324 decides a difference between a 3D convolution calculation result S_(L)(X, Y, Z) of the left suction pad 6 a and a 3D convolution calculation result S_(R)(X, Y, Z) of the right suction pad 6 b based on the following Equation 4.

$\begin{matrix} {{f\left( {X,Y,Z} \right)} = \left\{ \begin{matrix} {{{Suction}\mspace{14mu}{by}\mspace{14mu}{one}\mspace{14mu}{suction}\mspace{14mu}{pad}},} & {{{{S_{L}\left( {X,Y,Z} \right)} - {S_{R}\left( {X,Y,Z} \right)}}} > \epsilon} \\ {{{Suction}\mspace{14mu}{by}\mspace{14mu}{two}\mspace{14mu}{suction}\mspace{14mu}{pads}},} & \begin{matrix} {{{{S_{L}\left( {X,Y,Z} \right)} - {S_{R}\left( {X,Y,Z} \right)}}} \leqq {\epsilon\mspace{14mu}{and}}} \\ {{S_{L}\left( {X,Y,Z} \right)} \neq {{nan}\mspace{14mu}{and}}} \\ {{S_{R}\left( {X,Y,Z} \right)} \neq {nan}} \end{matrix} \\ {{{Suction}\mspace{14mu}{is}\mspace{14mu}{impossible}},} & {{S_{L}\left( {X,Y,Z} \right)} = {{S_{R}\left( {X,Y,Z} \right)} = {nan}}} \end{matrix} \right.} & (4) \end{matrix}$

Here, ε indicates a threshold value for deciding a difference between normals. The calculation unit 324 decides a case where the object to be grasped can be sucked and grasped by one suction pad, a case where the object to be grasped can be sucked and grasped by two suction pad, or a case where the object to be grasped cannot be sucked and grasped, based on the above Equation 4.

Calculation Example of Convolution

FIG. 11 is a diagram for describing a calculation example of a convolution according to the embodiment. In order to facilitate the understanding, an example of FIG. 11 illustrates an example of convolution calculation in a case where the object 102 to be grasped is a flat box. This case is a special case of a 3D convolution, and is the same as a result of a 2D convolution.

Since the box is placed flat, all of normals of a grasping surface of the box are upward, and the normals are expressed by (ϕ,θ)=(1,0).

From a convolution calculation result 211 a between the left hand kernel and the normal grid, a position of the TCP of the handling tool 2 that can be sucked by the left suction pad 6 a is specified. Specifically, in the example of FIG. 11, the position of the TCP is specified by a position where the normal is (ϕ,θ)=(1,0).

Similarly, from a convolution calculation result 211 b between the right hand kernel and the normal grid, a position of the TCP of the handling tool 2 that can be sucked by the right suction pad 6 b is specified. Specifically, in the example of FIG. 11, the position of the TCP is specified by a position where the normal is (θ,ϕ)=(1,0).

The calculation unit 324 decides whether or not a normal of the position of the TCP of the handling tool 2 that can be sucked by the left suction pad 6 a and the normal of the position of the TCP of the handling tool 2 that can be sucked by the right suction pad 6 b are parallel with each other by taking a difference between the convolution calculation results 211 a and 211 b.

In the example of FIG. 11, a position where a result of taking the difference is (0,0) is a position that can be sucked by the two suction pads 6 a and 6 b. A position where a result of taking the difference is (1,0) is a position that can be sucked by the left suction pad 6 a. A position where a result of taking the difference is (−1,0) is a position that can be sucked by the right suction pad 6 b. A position where a result of taking the difference is empty (nan) is a position that cannot be grasped.

If the positions that can be sucked by the left suction pad 6 a and the right suction pad 6 b are known, evaluation values of the ease of grasping of the positions that can be sucked by the left suction pad 6 a and the right suction pad 6 b are found by the heat map indicating the ease of grasping by the one suction pad 6 output by the evaluation unit 321. An average value of these evaluation values can be calculated to calculate an evaluation value of the ease of grasping the two pads. Then, the evaluation value can be projected onto a base image to generate a heat map by the plurality of suction pads 6.

Example of Handling Method

FIG. 12 is a flowchart illustrating an example of a handling method according to the embodiment. First, the normal grid generation unit 322 converts a depth image including one or more objects 102 to be grasped into a point cloud, generates spatial data including the object 102 to be grasped that is divided into a plurality of grids from the point cloud, and calculates a normal vector of the point cloud included in the grid using spherical coordinates (step S1).

Next, the hand kernel generation unit 323 generates a hand kernel of each suction pad 6 based on a position of each suction pad 6 in the handling tool 2 and a posture of the handling tool 2 (Step S2).

Next, the calculation unit 324 calculates the ease of grasping the object 102 to be grasped by a plurality of suction pads 6 based on a 3D convolution calculation using a grid including the spatial data calculated by the processing of Step S1 and the hand kernel generated by the processing of Step S2 (Step S3).

Next, the control unit 33 controls a grasping operation of the manipulator (the arm 1 and the handling tool 2) based on the ease of grasping the object 102 to be grasped by the plurality of suction pads 6 (Step S4).

As described above, in the handling device 100 according to the embodiment, the ease of grasping of the object 102 to be grasped by the plurality of suction pads 6 is calculated based on the 3D convolution calculation described above. Therefore, according to the handling device 100 according to the embodiment, it is possible to determine an appropriate handling operation without performing re-learning using teacher data for learning the ease of grasping again, even though the number or a position of suction pads 6 is changed.

For example, at a distribution site, when a large object 102 to be grasped is sucked by the plurality of suction pads 6 and a plurality of small objects 102 to be grasped are simultaneously sucked by the plurality of suction pads 6, efficiency of an automatic picking work can be improved. The handling device 100 according to the embodiment can be used at such a distribution site or the like.

Finally, an example of a diagram illustrating an example of a hardware configuration of the controller 3 according to the embodiment will be described.

Example of Hardware Configuration

FIG. 13 is a diagram illustrating an example of a hardware configuration of a diagram illustrating an example of the controller 3 according to the embodiment. The controller 3 includes a control device 301, a main storage device 302, an auxiliary storage device 303, a display device 304, an input device 305, and a communication device 306. The control device 301, the main storage device 302, the auxiliary storage device 303, the display device 304, the input device 305, and the communication device 306 are connected to each other through a bus 310.

Note that the display device 304, the input device 305, and the communication device 306 may not be included. For example, in a case where the controller 3 is connected to another device, a display function, an input function, and a communication function of another device may be used.

The control device 301 executes a program read from the auxiliary storage device 303 to the main storage device 302. The control device 301 is, for example, one or more processors such as a central processing unit (CPU). The main storage device 302 is a memory such as a read only memory (ROM) and a random access memory (RAM). The auxiliary storage device 303 is a memory card, a hard disk drive (HDD), or the like.

The display device 304 displays information. The display device 304 is, for example, a liquid crystal display. The input device 305 receives input of the information. The input device 305 is, for example, a hardware key or the like. Note that the display device 304 and the input device 305 may be a liquid crystal touch panel or the like having both of a display function and an input function. The communication device 306 communicates with another device.

The program executed by the controller 3 is a file having an installable or executable format, and is stored in a computer-readable storage medium such as a compact disc read only memory (CD-ROM), a memory card, a compact disc recordable (CD-R), and a digital versatile disc (DVD) and is provided as a computer program product.

The program executed by the controller 3 may be configured to be stored on a computer connected to a network such as the Internet and be provided by being downloaded via the network. In addition, the program executed by the controller 3 may be configured to be provided via a network such as the Internet without being downloaded.

In addition, the program executed by the controller 3 may be configured to be provided in a state of being incorporated in advance in a ROM or the like.

The program executed by the controller 3 has a module configuration including a function that can be realized by the program among functions of the controller 3.

Functions realized by the program are loaded into the main storage device 302 by reading and executing the program from a storage medium such as the auxiliary storage device 303 by the control device 301. In other words, the functions realized by the program are generated on the main storage device 302.

Note that some of the functions of the controller 3 may be realized by hardware such as an integrated circuit (IC). The IC is, for example, a processor executing dedicated processing.

In addition, in a case where functions are realized using a plurality of processors, each processor may realize one of the functions or two or more of the functions.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions. 

What is claimed is:
 1. A handling device comprising: a manipulator that includes a handling tool including a plurality of suction pads and an arm; a normal grid generation unit that converts a depth image including one or more objects to be grasped into a point cloud, generates spatial data including the object to be grasped that is divided into a plurality of grids from the point cloud, and calculates a normal vector of the point cloud included in the grid using spherical coordinates; a hand kernel generation unit that generates a hand kernel of each of the suction pads based on a position of each of the suction pads in the handling tool and a posture of the handling tool; a calculation unit that calculates ease of grasping the object to be grasped by the plurality of suction pads based on a 3D convolution calculation using a grid including the spatial data and the hand kernel; and a control unit that controls a grasping operation of the manipulator based on the ease of grasping the object to be grasped by the plurality of suction pads.
 2. The handling device according to claim 1, wherein the hand kernel generation unit expresses the posture of the handling tool by a first angle and a second angle of the spherical coordinates and generates the hand kernel according to the first and second angles for each of the suction pads.
 3. The handling device according to claim 1, wherein the calculation unit expresses the ease of grasping the object to be grasped by the plurality of suction pads by a first heat map, and the handling device further comprises an adjustment unit that adjusts the posture of the handling tool and a position where the object to be grasped is grasped by the handling tool based on the first heat map.
 4. The handling device according to claim 1, further comprising an evaluation unit that calculates an evaluation value indicating the ease of grasping the object to be grasped by one suction pad based on the depth image, wherein the normal grid generation unit comprises: a conversion unit that converts the depth image into three-dimensional point cloud data; a filter unit that deletes points whose evaluation values are smaller than a threshold value from the three-dimensional point cloud data to generate grasping target point cloud data; and a generation unit that generates the spatial data from the grasping target point cloud data.
 5. The handling device according to claim 4, wherein the evaluation unit calculates the evaluation value using a neural network having an input layer receiving an input of the depth image and an output layer outputting a second heat map indicating the evaluation value, and the filter unit specifies points whose evaluation values are smaller than the threshold value from the second heat map and deletes the points whose evaluation values are smaller than the threshold value from the three-dimensional point cloud data to generate the grasping target point cloud data.
 6. The handling device according to claim 1, wherein the handling tool includes a first suction pad and a second suction pad, the hand kernel generation unit generates a first hand kernel based on a position of the first suction pad in the handling tool and a posture of the handling tool, and generates a second hand kernel based on a position of the second suction pad in the handling tool and a posture of the handling tool, and the calculation unit calculates the ease of grasping of the object to be grasped by the plurality of suction pads based on a difference between a value of a 3D convolution calculation using the grid including the spatial data and the first hand kernel and a value of a 3D convolution calculation using the grid including the spatial data and the second hand kernel.
 7. A computer program product having a non-transitory computer readable medium including programmed instructions, wherein the instructions, when executed by a computer, cause the computer to function as: a normal grid generation unit that converts a depth image including one or more objects to be grasped into a point cloud, generates spatial data including the object to be grasped that is divided into a plurality of grids from the point cloud, and calculates a normal vector of the point cloud included in the grid using spherical coordinates; a hand kernel generation unit that generates a hand kernel of each of the suction pads based on a position of each of the suction pads in the handling tool and a posture of the handling tool; a calculation unit that calculates ease of grasping the object to be grasped by the plurality of suction pads based on a 3D convolution calculation using a grid including the spatial data and the hand kernel; and a control unit that controls a grasping operation of the manipulator based on the ease of grasping the object to be grasped by the plurality of suction pads. 